/**********
This library is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)

This library is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
more details.

You should have received a copy of the GNU Lesser General Public License
along with this library; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
**********/
// "liveMedia"
// Copyright (c) 1996-2018 Live Networks, Inc.  All rights reserved.
// A class for generating MPEG-2 Transport Stream from one or more input
// Elementary Stream data sources
// C++ header

#ifndef _MPEG2_TRANSPORT_STREAM_MULTIPLEXOR_HH
#define _MPEG2_TRANSPORT_STREAM_MULTIPLEXOR_HH

#ifndef _FRAMED_SOURCE_HH

#include "FramedSource.hh"

#endif
#ifndef _MPEG_1OR2_DEMUX_HH

#include "MPEG1or2Demux.hh" // for SCR

#endif

#define PID_TABLE_SIZE 256

class MPEG2TransportStreamMultiplexor : public FramedSource {
public:
    Boolean canDeliverNewFrameImmediately() const {
        return fInputBufferBytesUsed < fInputBufferSize;
    }
    // Can be used by a downstream reader to test whether the next call to "doGetNextFrame()"
    // will deliver data immediately).

protected:
    MPEG2TransportStreamMultiplexor(UsageEnvironment &env);

    virtual ~MPEG2TransportStreamMultiplexor();

    virtual void awaitNewBuffer(unsigned char *oldBuffer) = 0;
    // implemented by subclasses

    void handleNewBuffer(unsigned char *buffer, unsigned bufferSize,
                         int mpegVersion, MPEG1or2Demux::SCR scr, int16_t PID = -1);
    // called by "awaitNewBuffer()"
    // Note: For MPEG-4 video, set "mpegVersion" to 4; for H.264 video, set "mpegVersion" to 5;
    //     for H.265 video, set "mpegVersion" to 6.
    //     For Opus audio, set "mpegVersion" to 3.
    // The buffer is assumed to be a PES packet, with a proper PES header.
    // If "PID" is not -1, then it (currently, only the low 8 bits) is used as the stream's PID,
    // otherwise the "stream_id" in the PES header is reused to be the stream's PID.

private:
    // Redefined virtual functions:
    virtual void doGetNextFrame();

private:
    void deliverDataToClient(u_int8_t pid, unsigned char *buffer, unsigned bufferSize,
                             unsigned &startPositionInBuffer);

    void deliverPATPacket();

    void deliverPMTPacket(Boolean hasChanged);

    void setProgramStreamMap(unsigned frameSize);

protected:
    Boolean fHaveVideoStreams;

private:
    unsigned fOutgoingPacketCounter;
    unsigned fProgramMapVersion;
    u_int8_t fPreviousInputProgramMapVersion, fCurrentInputProgramMapVersion;
    // These two fields are used if we see "program_stream_map"s in the input.
    struct {
        unsigned counter;
        u_int8_t streamType; // for use in Program Maps
    } fPIDState[PID_TABLE_SIZE];
    u_int8_t fPCR_PID, fCurrentPID;
    // Note: We map 8-bit stream_ids directly to PIDs
    MPEG1or2Demux::SCR fPCR;
    unsigned char *fInputBuffer;
    unsigned fInputBufferSize, fInputBufferBytesUsed;
    Boolean fIsFirstAdaptationField;
};


// The CRC calculation function that Transport Streams use.  We make this function public
// here in case it's useful elsewhere:
u_int32_t
calculateCRC(u_int8_t const *data, unsigned dataLength, u_int32_t initialValue = 0xFFFFFFFF);

#endif
